Learn to plant and maintain strong, healthy trees that will thrive for generations.

Caring for Mature Trees During A Drought

A mature tree is defined as a tree with trunk whose diameter measures more than 16 inches around at the height of your chest.


Watch this video we made in partnership with Be Water Smart to learn more about watering mature trees.   

How much water does my large tree need?

Mature trees vary widely in their need for water, depending on size, age, species, and if there is irrigated lawn around it. Mature trees that are accustomed to regular lawn watering will continue to require some water during this time of drought.

Check the moisture of the soil (6 - 8 inches down) around the tree's dripline (area under the outermost leaves of the tree - see diagram). If the soil is dry and crumbly, apply water slowly so it seeps deeply into the soil.

How should I water my mature tree?

Watering slowly is important. An easy way to cut back on watering, but still ensure your tree is getting enough, is to place an inch high can (tuna fish or cat food can) beneath your tree, turn on your sprinklers and then turn off the water when the can is filled. Quitting tree watering “cold turkey” will be hard on your tree.

Don't rely on a clock or a calendar, water the tree when the soil moisture is low.

What if my city has banned outdoor irrigation?

The best way to be proactive and conserve water is to position a soaker hose in a spiral pattern starting a few feet away from the trunk and moving out to the dripline. (If possible remove the grass in this area and cover the hose with mulch.) Monitor the hose for run off and keep track of how long it takes to the water to penetrate 6 - 8 inches down so that you can repeat this technique when the soil becomes dry.

What if I'm worried about the health of my mature tree?

Hire a Certified Arborist who is knowledgeable about the needs of trees and educated and equipped to provide proper diagnostic and treatment services. Follow our guidelines to find and hire an ISA Certified Arborist.

Download our Tips for Drought Care for more information on keeping your trees alive and healthy during this historic drought.